Electrical switch



June 30, 1942. -r JOHNSON 2,288,529

ELECTRICAL SWITCH Filed March 1, 1940 2 Sheets-Sheet l T. F. JOHNSONELECTRICAL SWITCH June 30, 1942.

Filed March 1, 1940 2 Sheets-Sheet 2 Gama;

Patented June 30, 1942 UNITED STATES PATENT OFFICE ELECTRICAL SWITCHTomlinson Johnson, Atlanta, Ga.

Application March 1, 1940, Serial No. 321,759

3 Claims.

This invention relates to high tension electrical switches of the typeusually employed in sub-stations on high tension systems and, amongother objects, aims to provide a greatly improved switch associateddirectly with a bushing on electrical apparatus such as a transformer oroil circuit breaker. The idea is to utilize a high tension bushing ofthe existing equipment in lieu of a separate insulator or insulators andto dispense with some of the supporting members of the usual switchassembly, thereby effecting great economy in such switch installations.Another aim is to provide a switch of this type having provision foradjusting the relative positions of the switch jaw and blade tocompensate for differences in the height or length of bushings.

Other aims and advantages of the invention will appear in thespecification, when considered in connection with the accompanyingdrawings, wherein:

Fig. 1 is a side elevation of a switch assembly embodying the invention;

Fig. 2 is a fragmentary side elevation on an enlarged scale, showing apantograph jaw support;

Fig. 3 is a fragmentary view similar to Fig. 2, but showing thepantograph adjusted to another position;

Fig. 4 is a rear elevation of a three phase switch unit of the typeshown in Fig. 1; and

Fig. 5 is a vertical end elevation of the jaw support shown in Figs. 1,2 and 3.

Referring particularly to the drawings, the type of switch there shownis designed to be used in conjunction with a bushing or series ofbushings on electrical apparatus such as high tension transformers insubstations. However, it is to be understood that such switches may beemployed in conjunction with any kind of bushings, such as wall bushingsor the bushings of oil circuit breakers. In sub-station equipment theswitches for high tension lines leading to trans formers and oil circuitbreakers are necessarily very large and heavy. They require expensiveinsulators and when they are separately mounted, must be supported onspecial beams or supporting frame members. The cost of a singleinsulator, or groups of insulators, for such switches is quite large.This invention dispenses with one of the insulators usually employed ineach of such switches and to utilize the bushing of the electricalapparatus in its stead.

Referring to Fig. l, the switch is there shown as being mounted toco-act with a bushing ID of a transformer or oil circuit breaker II andin this example the bushing has an adjustable spring jaw l2 which may beof any conventional type or generally like that shown in my Patent1,914,777. Herein, the jaw is carried by pairs of pivoted links I 3 and[4 which, in turn, are pivotally connected to a socket member l5 adaptedto be clamped on the upper end of a capacity rod or terminal l6extending through the bushing ID by means of a clamping bolt [1, thelower end of the socket I 5 being split for that purpose.

The arrangement is such that the links l3 and i4 constitute a pantographfor adjusting the switch jaw both vertically and horizontally in thevertical plane of the switch blade. The link pivots are shown as beingin the form of bolts l8 so that when the jaw is properly adjusted, thebolts may be tightened to sustain itin its adjusted position. Thepurpose of the adjustment is to support the jaw properly on bushings ofvarious lengths or to compensate for any diiTerence in the height of theopposite ends of a switch blade when supported on a sub-stationstructure.

In this instance, an articulated switch blade IQ of a well known typecooperates with the switch jaw. As shown in dotted lines in Fig, 1, ithas a knee-joint near the middle which breaks slightly upon openingmovement and straightens upon closing movement. It is shown as beingmounted on a rocking insulator 20 which is pivotally supported by asplit saddle 2| on bearing members 22 carried by beams 23 on thesub-station frame structure 24. It will be understood, however, that theframe 24 may be specially designed to carry a gang of such switches andit is so shown in Fig. 4 for carrying the switches of a three-phasecircuit. The rocking insulator 20 is limited in its swinging movement bylateral wings 25 on the saddle 2| and adjustable stop pins or members 26mounted on the supporting beams 23. The insulator 20 is adapted to berocked by the usual hand crank 21 connected through well known worm andwheel gearing (not shown) in a gear housing 28 to a crank arm 29,operating link 30 and arm 3|. The arrangement is such that the switchblade may be swung through approximately to the dotted line positionshown in Fig. 1. When the switch is closed, the tip of the articulateblade closes by both swinging and horizontal movement to produce a verypowerful spring grip contact with the jaw. Incidentally, the tip portionof the blade I9 is shown as being connected by a flexible conductor 32'to a high tension line terminal 33 pivoted on the cap of the rockinginsulator 23 so that the opening and closing movement of the switch willnot bend the lead-in conductor 34.

To relieve the pantograph supported jaws [2 of undue racking strain andto counterbalance the weight of the respective rocking insulators andtheir switch blades in both the closed and open position, each insulatoris shown in Figs. 1 and 4 as having a pair of counterbalancing coilsprings 35 mounted on the tension rods 36 connected to arms 31 on theinsulator shafts. The rods 36 are slidable through pivoted sleeves 38having trunnions journaled in brackets 39 supported on the beams 23. Theupper ends of the coil springs act against these sleeves and their lowerends against nuts or abutments 4D screwed on the lower ends of the rods.In Fig. 4 the three rocking insulators are shown for convenience asbeing rocked to their vertical positions or half way between their openand closed positions. They are shown as being connected to operatetogether by means of shaft sections 4| of the proper length rigidlyconnected to the respective rocking insulator shafts and the handle 21is connected to only one of the shaft sections 4!, as is usual in gangswitch operation.

From the foregoing description, it will be seen that the switch assemblyis very simple in its construction and operation. The cost ofinstallation is greatly reduced. The pantograph mounting for the jaw notonly permits the necessary adjustments of the jaw, but prevents breakingstrains or shocks from being transmitted to the supporting bushings.

Obviously, the present invention is not restricted to the particularembodiment thereof herein shown and described. Moreover, it is notindispensable that all the features of the invention be used conjointly,since they may be employed advantageously in various combinations andsub-combinations.

What is claimed is:

1. An adjustable contact for high tension electrical switchescomprising, in combination, a support; jointed members pivotally andadjustably connected to the support; a switch jaw carried by the jointedmembers; and means holding the jointed members frictionally adjusted,whereby the jaw may be adjusted in any direction within the plane ofmovement of a switch blade.

2. In combination with a high tension, airbreak electrical switch of thecharacter described having an articulated swinging blade cooperatingwith a contact supported on a bushing, a cap member mounted on thebushing; a pair of opposed links pivotally and adjustably mounted on thecap member; and a second pair of links pivotally and adjustablyconnected to the ends of the first pair of links and also pivotallyconnected to the contact, whereby the contact member may be adjustedpantograph-fashion both vertically and horizontally in the plane ofswinging movement of the switch blade.

3. In combination with a high tension, airbreak, electrical switch ofthe character described having a counterbalanced, articulated, swingingblade mounted for endwise movement upon closing and cooperating with acontact support on a transformer bushing, a contact supporting membermounted on the bushing; pantograph links pivotally and adjustablymounted on the contact supporting member and adjustably connected to.the contact; and clamping bolts frictionally holding the pantographlinks in adjusted positions whereby the contact may be adjusted in alldirections in the plane of the swinging movement of the blade.

TOMLINSON F. JOHNSON.

